Julianna Margulies gives us a dose of 'ER' nostalgia for George Clooney's birthday

Julianna Margulies and George Clooney went from TV lovers to lifelong friends.

The "Good Wife" star, 53, didn't pass up the chance to wish her former "ER" co-star a happy 59th birthday on Wednesday, taking to Instagram to share a snap that likely gave fans of the iconic medical series heart palpitations.

"Happy Birthday to my sweet pal George Clooney," she wrote alongside a nostalgic old photograph of them smiling at the camera. "This picture was taken right after we filmed our very last scene together in Seattle for #ER."

Margulies also told her followers to "stay safe" and to "listen to science" by not injecting Lysol or drinking bleach. While she doesn't mention him by name, it is likely she is referring to President Donald Trump's recent musings about using disinfectants to fight the coronavirus.

Clooney and Margulies began starring on "ER" in 1994 alongside an original cast consisting of Anthony Edwards, Noah Wyle, Sherry Stringfield and Eriq La Salle.

While Clooney, who played Dr. Doug Ross, a pediatrician, left in the middle of season 5, Margulies, who played nurse manager Carol Hathaway, left at the end of season 6. Clooney made a surprise appearance for Margulies' farewell episode.

The two eventually returned for an episode in the show's 15th and final season in 2009.